Thread: Would like some feedback on Pistons...

Pick up a L32 block and don't skimp out on a tune, buy an aeroforce, wideband and save yourself an engine.

I would of bought a L32, but the cheapest in this area was $1200. They're a rare engine around here. Imports though are everywhere. This is before I knew about car-part.com.

I have 2 engines, 1 from the 98 Regal and 1 from the 98 GTP. The Regal is all original with an L67. The GTP has what looks like a Gen II junkyard block, but was rebuilt. It was supposed to be a new Gen III block from GM when I bought the GTP, but didn't notice until I pulled the engine, I'm not to happy with the previous owner. I'm currently building the engine for the Regal, the GTP will come later. I took the pistons from both engines to my machinist to have them checked. He noticed the dish of the pistons from the GTP wasn't as deep as the pistons from the Regal. One of the pistons from the GTP was chipped exposing the top ring. The Rods from the pistons on the GTP aren't the cast steel ones so I wanted to use them as I've heard of their better strength. The cast iron rods from the Regal can't be reused as one of them spun a bearing.

The engine that was in the GTP was running, but after having a transmission that was supposed to have a warranty fail and other things, I didn't trust the previous owner so I pulled the heads to check things out. Three of the cylinders have scores in them and one of the pistons was chipped. There were no signs of that chip falling off in the cylinder so it appears he actually assembled the engine like this.

My plans are to use the block from the Regal which has already been checked for crank and cam line, decked, and honed by my machinist. I bought some 2007 L32 heads, had him clean and pressure test them, I port and polished, and then took them back to my machinist for a valve job, milled the heads, and checked the valve guides. I was trying to determine which pistons to use before and I received different opinions. I was thinking of using the 9.4 ratio because 2 of my older friends (one of them is 60) and my machinist who's 61 who've built a number of engines recommended them, because you can only go so small of a pulley and then you run out of boost. Go with higher compression and create less heat. My machinist has a Grand National with 11 to 1 compression, it of course is turbo though. But if the 9.4 pistons are weaker than the SC pistons, then guess that scratches that idea.

Sorry for the long winded story, but I don't want to miss any details.